Update GPU process debugging documentation
Updates documentation on attaching a debugger to the GPU process based
on recent attempts to do so.
Change-Id: I2307d8823bd50759e2bee442b7dfd56ff355f927
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6336900
Reviewed-by: Yuly Novikov <[email protected]>
Commit-Queue: Yuly Novikov <[email protected]>
Auto-Submit: Brian Sheedy <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1429884}
diff --git a/docs/gpu/debugging_gpu_related_code.md b/docs/gpu/debugging_gpu_related_code.md
index ec9d07a..3bf2316 100644
--- a/docs/gpu/debugging_gpu_related_code.md
+++ b/docs/gpu/debugging_gpu_related_code.md
@@ -218,18 +218,30 @@
To actually debug the GPU process:
-On Linux this works for me:
+On Linux, gdb can be automatically attached via the `--gpu-launcher` argument:
* `out/Debug/chromium --no-sandbox --gpu-launcher="xterm -e gdb --args"
http://localhost:8000/page-to-repro.html`
-On OSX this works for me:
+Similarly, gdb can be attached with the same argument on OSX:
* `out/Debug/Chromium.app/Contents/MacOSX/Chromium --no-sandbox
--gpu-launcher="xterm -e gdb --args"
http://localhost:8000/page-to-repro.html`
-On Windows I use `--gpu-startup-dialog` and then connect to the listed process.
+On Windows, `--gpu-launcher` used with `windbg` does not appear to work
+properly, as the browser process will always fail to start the GPU process.
+Instead, you have two alternative options:
+
+1. Use `--gpu-startup-dialog`, which will cause a dialog window to be shown on
+ GPU process startup with the PID that you can attach to. This should work for
+ most use cases, but since it will add at least several seconds of delay, it
+ is possible to change behavior if the issue being debugged is timing related.
+2. Run the browser process through `windbg` and automatically attach to child
+ processes via `windbg -g -G -o <command to start Chrome>`.
+
+Similar approaches are likely possible with other debuggers, but the specifics
+are not listed here.
### `GPU PARSE ERROR`
